Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Induced current question

  1. Oct 31, 2005 #1
    I'm working on a question that I could use some help on. The problem basically says there is a solenoid with a current running through it given by an equation. There is a wire that is coaxial with and surrounding the solenoid, and the wire makes two loops around the solenoid. A resistance for the wire is also given. The question wants to know what the current in the wire is. Now, I know that if the wire was only looping around the solenoid once, I could just use faraday's law to calculate the induced emf, and then use I=[tex]\xi[/tex]/R. What I can't figure out is how does the fact that there are two loops in the wire affect the induced current? Thanks for any replies.
  2. jcsd
  3. Oct 31, 2005 #2


    User Avatar
    Gold Member

    The equation for induced current if the wire is wrapped n times around the magnetic field is:
    [tex] I = \frac{\xi}{R} = \frac{n \dot{\phi_{t}}}{R} [/tex]
    Last edited: Oct 31, 2005
  4. Oct 31, 2005 #3
    Thanks for the quick reply. I'm just a tad confused about your notation. Are you saying that in this case I = 2[tex]\xi[/tex]/R? Or that if the emf is known, then it is always simply I=[tex]\xi[/tex]/R?

    Edit: Oh, ok. I didn't see your edit there. Thanks for the help.
    Last edited: Oct 31, 2005
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook